Gayle, What a pretty quilt. If your machine does decorative stitches select a wide one and use either a varigated or shiny decorative thread to quilt in the ditch. It will also dress up the back if it is a solid color. You could just quilt on the vertical and then the horizontial lines or you could do both and one vertical through the middle of each block.
The floral fabric is so lovely that a flower shape, while a great idea wouldn't show up all that well.
One other thing you might do is "couch" colorful fuzzy yarn into some of your quilting lines. I love the unusual yarns they sell now but don't do much crocheting anymore. I will buy one ball of the fancy yarn and crochet it into a single chain. I then couch it on things I want to embellish.
To couch all you have to do is lay the yarn or chain along the seamline you are going to quilt and sew with your decorative stitch or zig zag over top of it. Be sure to catch the yarn in the stitching, as often as possible. It is also a good way to hide points that didn't come out just right.
It is going to be a lovely quilt.